**Background:** Family support is a critical determinant of children's general and oral health. Orphan children, defined by UNICEF as those who have lost one or both parents or have been deserted before age 18, are considered deprived and socially handicapped with high disease liability. Institutionalized orphans face compromised socioeconomic status, overcrowding, low caretaker-to-child ratios, poor nutrition, inadequate psychological support, and underestimation of dental care importance by caretakers. While several studies have examined oral health in orphan populations globally, literature on Egyptian orphan children's oral health remains vague. This study aimed to assess dental caries experience in two groups of Egyptian institutionalized orphan children compared to parented school children.
**Methods:** This observational case-control study included 156 children (52 per group) recruited from a non-governmental orphanage, a governmental orphanage, and a private primary school in Giza, Egypt during the last two weeks of November 2022. Inclusion criteria were cooperative, apparently healthy children aged 6–12 years with no chronic illness or medication, whose guardians consented to participate. Children with enamel/dentine developmental defects were excluded. Sample size was calculated using G*Power version 3.1.9.7 with alpha 0.05, beta 0.2 (80% power), and effect size f of 0.32, yielding a minimum of 52 children per group. Ethical approval was obtained from IRB IORG0010868, Faculty of Oral & Dental Medicine, Ahram Canadian University (Research Number: IRB00012891), and the trial was registered at ClinicalTrial.gov (NCT05652231). Dental examinations followed WHO criteria and methods, conducted on ordinary chairs under normal daylight using mirrors, probes, tweezers, and cotton rolls. Inter-examiner and intra-examiner calibration was established (Kappa = 0.89). Caries experience was recorded using DMF and def indices. Restorative care index, unmet treatment needs index, and significant caries index were calculated. Demographic data, medical/dental history, brushing habits, snacking habits, and dental visit history were collected via interviews. Statistical analysis used SPSS version 20 with Chi-Square test, Fisher exact test, and Mann-Whitney U-test at 5% significance level.
**Key Results:** The study included 73 males (46.8%) and 83 females (53.2%), with no significant differences in gender or age distribution across groups (p = 0.83 and p = 0.85, respectively). Caries prevalence was highest in the governmental orphanage (78.85%), followed by non-governmental orphanage (75%), and private primary school (61.54%). Mean DMF total scores were 1.86 ± 2.96 for non-governmental orphanage, 1.80 ± 2.54 for governmental orphanage, and 0.75 ± 1.29 for school children (p = 0.025). Mean def total scores were 1.69 ± 2.58, 0.41 ± 0.89, and 0.85 ± 1.79 respectively (p = 0.01). The significant caries index was 4.29 for governmental orphanage, 2.5 for non-governmental orphanage, and 2.17 for private school (p = 0.001). The restorative care index was 0% for governmental orphanage, 18.80% for non-governmental orphanage, and 1.33% for private school. Unmet treatment needs index was 100% for governmental orphanage, 58.6% for non-governmental orphanage, and 93% for private school. Notably, 100% of governmental orphanage children reported brushing their teeth (69.2% once/day) and 0% consumed cariogenic snacks daily, while 88.5% of non-governmental orphanage children brushed (30.8% twice/day) and 73% consumed cariogenic snacks daily. None of the governmental orphanage children had ever visited a dentist, compared to 69.2% of non-governmental orphanage children and 44.2% of school children.
**Clinical Implications:** This study demonstrates that institutionalized orphan children in Egypt have significantly higher dental caries prevalence and worse caries experience compared to parented school children, confirming the hypothesis that absence of parental care negatively impacts oral health. The stark contrast between the governmental orphanage (low caries experience but 100% unmet treatment needs and 0% restorative care) and the non-governmental orphanage (higher caries experience but better restorative care at 18.80%) highlights that access to professional dental care, not just disease prevalence, is a critical issue. The findings underscore the need for comprehensive oral health preventive strategies, educational programs targeting orphanage caretakers, and mandatory enrollment of orphanage children in regular professional dental care programs. The study's limitations include lack of comprehensive diet history analysis, oral hygiene status measurement, and oral health knowledge assessment among children and caretakers. Results may vary across populations based on demographic and socioeconomic factors, though the main hypothesis that orphan children are underprivileged across different cultures is expected to remain valid.